Selective time-impact fuze for hand grenades



Sept. 18, 1956 J. F. MocAsLlN SELECTIVE TIME-IMPACT FUZE FOR HANDGRENADES Filed Jan. 24. 195o lthe-following description and accompanyingSELECTIVE TIME-IMPACT FUZE FOR HAND GRENADES James F. McCaslin,Alexandria, Va. Application January o. '140,291 i 8 claims. (ci. 1oz-rz)(Granted under Title 35, U. S. Code (1952), sec. 266) The inventiondescribed herein may be manufactured and used by or for the Government,for governmental purposes, without the payment Ito me of any royaltiesIthereon.- e' j This .invention relates lto fuzes and-more specificallyto a time-impact fuze for hand grenades or `the like.- Y

It has 'been found lthat hand grenades employing the all-ways type ofyfuze have proven extremely dangerous to the using personnel in thatthe-fuze armed and tired too quickly while still in effective proximityof the thrower. The selective--time-impactffuze yof this inventionutilizesthe 4-all-ways type of fuze in combination with a Vdetent meanswhich provides a suficient delay -to allow the grenade to reach -a safedis-tance from they thrower before the fuze becomes armed -for impactytiring. There lis also incorporated in the fuze a selective meansenabling thethrower to select either a powder delay `train or thecombination of powder delay train and the, all-ways impact fuze. Anothernovel feature of the tuze of this invention is the provision of ventswithin 'the fuze body for receiving any smoke `or sparks and conningthem within the body.

The specific nature of the invention as well asl other objects andadvantages thereof will clearly appear from drawings in which: n

Figure l is a )sectional view of lthe lfuzemounted in the cap of al handgrenade.

Figure 2 is a view taken along line2-2 of yFigurel;`

Figure 3 is a view taken along line 3-3 Aof Figure 1.

Figure 4 is a plan view of `the :fuse housing with its yclosure removedand showing' the internal vents.

Figure 5 is Va `fragmentary sectional view of a m'odied all-ways fuzepositioned in -the all-ways fuze cavity of the lselective time-impactfuze. e A

Referring now to the drawings by characters of reference there is shownin Figure l an embodiment of my invention wherein 1 generally indicatesthe Ibody of a hand grenade having a die cast cap 2 threadedlyreceiving, as indicated by reference numeral 3, a bouchon 4 havingmounted thereon an operating lever 5 extending across its vtop and downthe side of the grenade body. The bouchon 4 is formed with a recess 6 inits Itop providing two upstanding walls 7 and 8. A pin 9 supportedjbythe walls carries a spring engaging a striker 11 rfor striking a primercap 12 positioned in ythe bot-tom of -the recessV 6 when the operatinglever 5 has been released by the thrower. rPhe lever 5 and striker 11are held inoperative by means of a safety pin 13 positioned in thevertical walls 6a and 6b of the lever 5 and thewalls 7 and` 8 of thebouchon, as best seen in Figure 2, until such time as-it is desired touse rthe grenade whereupon thesafety pin is withdrawn, while 'theVthrowers Ihand holds the downwardly projection portion of Ithe lever andbody. The bouchon has a bottom recess 14 wherein is keyed,f as

a-t 15, a housing v1'6 havingfa closure 17. Fixed Vin the lowr Portionvlef' the hltsilefl Meer@ lahaine a relayn 18a x'ed therein. Anopening-19 in thev lower l nited States Patent V(Y portion forms a ashpassage between the 'primer detonat-or 20a of jthe all-ways fuze 20-inythe cavity 21of'the housingassembly 16 and 17 and `the relay 18a. Therelay 18a is'also' in communication'with the primer cap 12 .by means of'a power time train 12d'whi'ch extendsy through the housing 16 andbouchon 4. The `all-ways fuze 20 comprises a sleeve 22 housing a -ringpin 23 slidable therein. The sleeve`2r2 has a primer detonator. 20aixed"in one e'nd in"line`withand opposite'the opening. 19?'I The"tiring" pin has at'raves'e bore 24' adjacent itsA fear endwithin whichare retained ltwo balls 25 and I 26 kept in spaced lrelationship by anarming pin 241havprick end of said ring pin is` resiliently spaced fromtheV prime-r detonator a by means of a helical spring 23a.-

ing its shank normally slidably positioned. inthe bore 30 of vtheclosure 17 Vland `avbor"e29 in thefrealportion of said pin andintersecting the traverse' bore "24." The The shank of the arming pin 27has a necked section 31 adjacent its end in the tiring pin and a flangedtopA 32 in engagement with a combustible detent 32a. A helical spring 33about the 'shank Vandbetween the `flange top 32 and a base 30a in thebore 30 maintains contact between th-e anged top 4and a combustibledetent 32a. The com'bustible detent releasably maintains-the arming 'pininthe bores 29 and 30 when the fuzeisY set forl impact firing. Thecavity 21` has a-domeshaped top,V wall'Zla so ythat when the arming pinhas released the all-ways jfuze, the firing pin will be cam-med towardthe primer detonator should the side of the grenade strike ythe target.arming pin is ejected from the tiring pin into `the cavity 4a of thebouchon and the ball.25 and.26 rolled toward the longitudinal axis lofthe iiring'pito permit thering pinto slide in the sleeve 22 and strikethe primer detonator upon impact. The combustible detent 32a covers thebore 30 in contact with the hanged end of the tiring pin and is retainedin the position by the bottom face of the bouchon. At yone edge thedetent is in contact with a black powder igniter pellet 34 in a recess34a of the closure 17. A short time delay train 35 located arming pin.The opposite end of :the shaft extends out-V wardly of the bouchon andhas fixed lthereto an arm 4 0 perforated at its free end 'as at 41 andreceiving the,

safety pin 13. The housing 16 has formed therein radially spacedchambers 42 for receiving and storing smoke and sparks of thecombustible elements of the fuze to prevent the same escaping to theatmosphere and lthereby warning lthe enemy. The chambers also containsufficient oxygenfor normal combustion of the combustible elements andprovide a sufficiently large expansion chamber to prevent excessivepressure build up. The chambers are in com-` munication with each otherby means of a channel 43 formed in the bottom of housing recess 17a. Thecavity 21 is in communication with the chambers 42 by'means of a4 duct44 connecting the cavity 21 with one of said chambers. The recess 4a inthe bouchon isin communication with channel 43 and the said chambers bymeans of a duct 45 in the bouchon aligned with a duct 46 in the closuremember.

In `operation the grenade is held in the hand of the thrower with thengers embracing lthe grenade body andl lever.v y The safety pinis pulledandthe .grenade thrown releasing the lever which iesolf allowing thestriker lto re the primer cap. The primer cap ignites thedel'ay train,12a whichgburnsjto functionyythe boosterL When the combustible detentfunctions, the ,e

c 3 Y t simultaneously ignites the short time delay train which ignitesthe black powder igniter pellet which in turn ignites thecombustiblejdetent. The short time delay and the .combustible detentburn with suicient delay to allow the grenade `to reach a `saie distancefromthe thrower and then permits'the arming pin to be forced up into'thecavity 4a of `the bouchon by action of the rspring under the iiangedhead of the arming pin, thus arming they all-ways fuze mechanism forfunctioning under impact. The tiring pin moves down in the sleevecontaining the primer detonator to strike the said detonator if the'lbottom of the grenade strikes' the target. It the grenade strikes `thetarget on its fuze, the primer detonator moves towards the tiring pin,and if the grenade strikes the target at any angle to the verticalL axisof the grenade the firing pinv is cammed into the primer detonator kasthe rounded end of the tiring pin moves along the dome shaped top of thecavity 2. T he selector held in position bythe-safety pin through theselector arm, dogs the aliways fuze arming pin, and in that' positionthe grenade is functioned by the time'delay train 12a only. if, afterpulling the'safety pin and while the grenade is still gripped in thehand, the selector is moved 90 in a counterclockwise direction thearming pin is free to move into the cavity 4a upon the burning of theconibustiblc detent. As a further safety against' the firing of theall-ways fuze by centrifugal means due to excessive spin from a snap ofthe wr-ist in throwing, the arming pin is necked so as to be caught at`the edge of the arming -pin perforation inthe dome, due to anyexcessive off axis pressure on the all-ways fuze assembly, thuspreventing thefull arming of the impact mechanism until the effect ofspin is dissipated, but upon such dissipation still allowing normalarming and subsequent impact 'functioning. i

In Figure 5 there is shown a modified all-ways fuze, generally indicatedby the reference character 50positioned in the cavity 21 of theliousingassembly members 16 and 17. The modiiied all-ways fune comprisesa sleeve 51 having a primer detonator 52 fixed in one end and incommunication with the ash passage 19. The opposite end of sleeve 51 isprovided with an inwardly directed bevel 53. Slidably positioned in thesleeve 51 is a sleeve 54, its longitudinal perforation receiving anarming pin 27, The sleeve 54 is longitudinally slotted, as indicated bythe reference numeral 55, to receive the firing pin S7. Adjacent theprimer detonator is a helical spring 56 in the sleeve 51 whichresiliently supports the firing pin 57 stamped from sheet metal. Thespring 55 also resilien-tly spaces the sleeve members 51 and 54 in thecavity 21. The liring pin is formed with a prick point S8 at the endadjacent the primer detonator and oppositely directed arm's 59 and 60 incontact with spring 56. The body 61 .and `the circular head 62 areslidably positioned in the slot 55 aud normally held diagonally of thevertical axis of the fuze by the arming pin 27 which has one end incontact with the head 62. The arm 60 is always in contact with thevbottom of sleeve 54. In operation the arming pin is ejected from thesleeve 54 and the arm 60 is pivoted about the bottom of sleeve 54 due tothe action of spring S6 causing the body and head to move through theslot 55 and align the prick point with the primer detonator. Upon impacteither the primer detonator carried `by sleeve 51 moves toward thetiring pin or the tiring pin carried by sleeve 54 moves toward theprimer detonator.

l claim:

l. ln a hand grenade employing a pivotally supported and spring urgedprimer striker means normally held in safe position by means of a safetypin which is withdrawn prior to throwing the genade, a selectivetime-impact fuse compris-ing a bouchon threadedly rlixed .to `'the capof said grenade and supporting said striker means in a recess formed inits top, a primer iixed in said recess in cooperative relationship withsaid striker means, said bouchon having a downwardly directed cavity forreceiving an arming pin of an all-ways fuze, a depending housing in thebase of said bouchon and directed 'inwardly of said cap, said housingbeing provided with a cavity having truncated walls and a dome shapedtop wall, an all-ways fuze positionedinsaid cavity, a perforationin saiddome shaped top wall in alignment with said downwardly directed cavityand said all-Ways fuze, anL allways fuze yspring loaded' arming pinpositioned partially in said all-ways fuze andr partially in saidperroration, a

v combustible detent positioned across the open end of saidperforation'and in engagement with said arming pin, a black powderpellet iixed adjacent one edge of said dc- `tent, a rst delay powdertrain through said bouchon and said housing and spaced from said cavity,said first delay powder train connecting said primer `with said boosterfor time delay functioning Aof said grenade, a second delay powder trainof relative short burning period in said bouchon, said second delaypowder train connecting said primer and said black powder pellet toignite said combustible detent for impact tiring of 'said grenade.

2. The time-impact fukze of claim l wherein said bouchon is providedwith a radial bore, a selective timeimpact means rotatably mounted insaid bore, said meansv safety pin, said arm manually movable uponwithdrawal of said safety to rotate said shaft to move the finger out ofalignmentwith said arming pin'providing an unobstructed path of travelfor the arming pin when said pin is released by the combustible detentto arm said grenade for impact firing.

3. Thevtime-impact fuze of claim 2 wherein said fuze is provided withsmoke and spark concealment means comprising radially spaced chambers insaid housing, channel means interconnecting said chambers, a first ductpassing through said bouchon and said housing member having one end incommunication with said downwardly directed cavity and said perforation,the opposite end of said tirst duct in communication with said channel,a second duct located in said housing, said second duct having one endin communication with said cavity containing the all-ways fuze and itsopposite end in communication with one of said chambers, said ductsreceiving and directing smoke and sparks formed by the combustibleelements to said chambers.

4. The time-impact fuze of claim 3 wherein said fuze is provided withsafety means to prevent premature functioning of the all-ways fuze dueto centrifugal force created by excessive spin when the grenade isthrown, said safety means comprising a tapered neck formed in saidarming pin adjacent the end normally positioned in said all-ways fuze,said neck engaging the edge of the perforation in the dome after the pinhas been released by the combustible detent, said neck disengaging saidedge after the spin of the grenade has been sufficiently reduced, saidpin entering the downwardly directed cavity to release the all-ways fuzefor impact functioning.

5. In a hand grenade a time-impact fuze comprising a bouchon threadedlyengaged to the cap of the body of said grenade and supporting a springurged striker means normally held in safe position by a safety pin whichis withdrawn prior to throwing the grenade, said striker meansreleasable upon throwing said grenade to fire a primer fixed in saidbouchon and extending into said cap, a booster lixed in said housing, aiirst firing delay train communicating said primer with said booster fortime delay tiring, a combustible detent in said housing, a second firingdelay train of shorter burning period than said first train andcommunicating said primer with "said combustible detent, an all waysfuze in said housing hav-` ing an arming pin in operable relationshipwith said detent, selector means comprising a shaft rotatably mounted insaid bouchon and held against longitudinal movement, said shaft having anger extending from one end substantially across said detent and in thepath of said arming pin, the opposite end of said shaft provided with anarm normally in engagement with said safety pin, said arm movable uponwithdrawal of said safety pin to rotate said shaft to move the fingerout of alignment with said arming pin when said pin is released by thecombustible detent to arm said grenade for impact firing. Y

6. In a hand grenade a time-impact fuse comprising a bouchon threadedlyengaged to the cap of the body of said grenade and supporting a springbiased striker normally held in a safe position by a pin adapted to bewithdrawn prior to throwing the grenade, said striker releasable to lirea primer xed in said bouchon and extending into said cap, a boosterfixed in said body, a lirst firing delay train communicating said primerwith said booster for time delay firing, a combustible detent in saidbody, a second firing delay train of shorter burning period than saidrst train and communicating said primer with said combustible detent, anall-ways fuse in a cavity formed in said body and having an arming pinin operable relationship with said detent and means for selectivelyrendering said all-ways fuse operable to arm said grenade for impactfiring.

7. The time-impact fuse of claim 6 wherein said body is provided withinterconnecting chambers communicating with the said all-ways fusecavity and being entirely within said fuse, said chambers containingsucient oxygen for normal combustion of said tiring delay trains andproviding a volume to prevent excessive pressure build up and to receiveand store the products of combustion.

8. The time-impact fuse of claim 6 wherein said means for selectivelyrendering said all-ways fuse operable comprises a shaft rotatablymounted in said bouchon and held against longitudinal movement, saidshaft having a ringer extending from one end substantially across saiddetent and in the path of said arming pin, the opposite end of saidshaft provided with an arm normally in engagement with said safety pin,said arm movable upon withdrawl of said safety pin to rotate said shaftto move the linger out of alignment with said arming pin.

References Cited in the le of this patent UNITED STATES PATENTS1,517,810 Wiley Dec. 2, 1924 1,537,208 Wiley May 12, 1925 1,768,678Froelich July 1, 1930 2,005,053 Schlafer June 18, 1935 2,412,636 ShortDec. 17, 1946

